There are a plurality of methods or processes for the manufacture of prostheses to be implanted in a patient suffering from a defect in the bone structure, mainly in the region of the skull. The defect may be due to a birth defect or surgical procedure, usually used when carrying out the removal of cancerous tumors that require removing a portion of both brain or surrounding skull.
In this regard, currently all methods or processes for the manufacture of such implants, which are mainly made of titanium because of the rigidity and maneuverability of the material, include steps that require very high temperatures. Manufacturing temperatures are typically higher than 450° C., to carry out the molding of the material adapted to a prescribed form of the prosthesis to be implanted by means of a pair of male and female molds which give it the desired shape.
However, this process is not entirely desirable given that in order to bend and shape the material, i.e. titanium, it is required that the molds reach very high temperatures. High temperatures increase the costs of production and operation, due to energy consumption, wherein such costs are directly transferred to the patient requiring the procedure.
Moreover, processes existing in the state of the art have a high environmental impact. Every time it is desired to perform a implant procedure it is also required to create a prosthesis to be implanted that, as noted above. This requires a very high operating temperatures and the power consumption is very high as well.
Thus, there are a number of disclosures focused on methods or processes for the manufacture of prostheses to be implanted in a patient, especially in the head thereof. Document EP 1457214 relates to an implant material comprising a porous article of a bioactive organic-inorganic, degradable and absorbable complex and a method for manufacturing such an article. The implant material comprises a porous article previously mentioned, in which a bioactive bioceramics powder is uniformly dispersed in a biodegradable and bioabsorbable polymer, and wherein it has continuous pores and the bioceramics powder is partly exposed at the inner surface of the pore.
The method described in this document is focused on the production of an implant material comprising a porous article of the organic-inorganic complex. In the method, a fabric-like fiber aggregate tissue is formed from a mixed solution prepared by dissolving a biodegradable polymer and bioabsorbable in a volatile dissolvent and dispersing a bioactive bioceramics powder therein. This is formed in a mold of porous fiber aggregate molding by compression thereof, the fiber aggregate molding is immersed in the volatile dissolvent, and then said dissolvent is removed.
However, the disclosure in this document has a major disadvantage which is based on the use of a number of solvents and dissolvents in order to process the porous fiber aggregate with a number of bioactive bioceramics corresponding to the material in which the prosthesis or implant is made. This makes the process described therein very complex and requires special equipment and elements which increase the costs of producing the implant itself.
On the other hand, document MXPA 03010379 discloses a method for the manufacture or production of a surgical mesh and plate implant, which comprises the steps of a) applying a masking to the two faces of a metal sheet, b) ablating selective masking on the sides of the foil but leaving an open hole for a screw, c) fixing a first tape to cover the first side and the masking on this, d) fixing a second tape to cover the second side and masking thereon, e) recording the acid portion of the screw hole to form a first side hole, f) removing the first film, g) acid recording the hole and other exposed portions of the first side, h) removing the second strip, i) acid recording the hole and other exposed portions of the second face, and j) removing the remaining masker.
However, just like in the document EP 1457214 previously defined, this requires specific steps of various materials that increase the costs of production of the implant using this process, taking into consideration the application of a masking of the surfaces of the sheet material in which the implant is made.
Document CN 101264035 mentions a method for the production or preparation of a titanium mesh cranial prosthesis. The method is characterized in that the image of the thin layer scanning CT is introduced in the region of two-dimensional coordinates. A midfield line, a baseline, a reference line and a plurality of brain construction lines are drawn. Reference sites of the skull to be repaired are determined at the intersection of each construction line and the fine skull in the symmetric region of the defect region; and the corresponding points of the prosthesis element is generated in the region of the skull defect; the image layer corresponding to the scan point element, the number of construction lines and the vertical distance between the point and the line item are recorded. Each sheet of film in different CT layers are entered in the coordinate region in order to carry out the operation to form the data of all points of the elements of cranial morphology in the defect region; and the titanium mesh is pressed according to multipoint data element points, to obtain the titanium mesh cranial prosthesis.
However, this document is mainly focused on software and method steps that are necessary to obtain a model of titanium mesh prosthesis to be implanted, from the software, which is not desirable in manufacturing an affordable and accessible prosthesis for any type of patient. However, production costs are very high, since they are linked directly with the software and licenses that manufacturers wish to supply. This is a disadvantage since it does not have availability at all times of the process but depends on the availability of the software to create the prototype of the implant.
Finally, document CN 101354579 relates to a method for obtaining a titanium alloy for defective human bone prosthesis by embossing mold, wherein the method provides a titanium alloy prosthesis bone having a high accuracy and meets the requirements of an individual patient for patients with bone defects and especially in those with complex defective bone structures. The method comprises the step of constructing a curved surface of the defective bone prosthesis according to the CT DICOM data format or MR DICOM data format of the patient's bone, where a titanium plaque mold is designed according to the curvature of the surface, and then the mold data are introduced into a digital tool control machine. Thus, a sealed mold needing design is machined by the machine-tool and in the titanium plate is accomplished by forming the mold pattern.
Accordingly, the data format DICOM CT or MRI DICOM data format of the patient's bone is subjected to 3D reconstruction, and a picture of the reconstructed bone is inserted into the digital control machine tool, and the digital control machine manufactures a bone prosthesis, and then a test is made between a bone prosthesis and a model of the patient's bone to ensure that the prosthesis is fully matched with the patient's skull.
However, the method described in this document, although it is very novel by including the use of a system for collecting and analyzing data for the prosthesis that best suits the patient, is carried out by known techniques for casting and to get the desired shape to a titanium plate, which in turn requires very high temperatures of operation in order to bend the titanium molds into the desired shape which, as indicated above, increases the costs of operation and affects the environment due to the high power consumption.
Thus, it is evident that there is a need in the state of the art to implement a process for manufacturing a prosthesis to be implanted in a patient, especially in the skull area, wherein the process uses commercially available and inexpensive elements to reduce operating costs and thereby enable more people to access this kind of surgical procedures to overcome a drawback, either congenital or obtained by the removal of cancerous tumors, which also requires the process to be eco-friendly by reducing the operating temperature, whereby electric power consumption is reduced.